Estrogen Replacement Therapy



Estrogen Replacement Therapy (ERT) is also commonly known as Hormone Replacement therapy (HRT) which is actually an incorrect term as there is a long list of hormones in the body. However, HRT does refers to replacement of estrogen in postmenopausal women.


Estrogen Replacement Therapy (ERT) has traditionally been used to prevent osteoporosis.


It is also the most effective treatment for hot flashes. However, these days there is a lot of controversy about the benefits of Estrogen Replacement Therapy (ERT). In a recent landmark study, Womens' Health Initiative (WHI), it was clearly shown that ERT increases risk for breast cancer and contrary to previous belief, increases risk for stroke, heart attack and dementia. Since the publication of this study, most endocrinologists, including myself, recommend ERT only in selected cases. I primarily use it to treat the symptoms of menopause, especially debilitating hot flashes. In these cases, I recommend it only for a few months.


For the prevention of osteoporosis, I recommend using other drugs such as calcium, vitamin D, Fosamax, Actonel, Evista and Forteo. Please refer to the link for osteoporosis for more details in this regard.


Patients on ERT have a threefold increase in the risk for "blood clot formation." Therefore, women with a history of "blood clot formation" should not receive ERT.


Patients on ERT also have an increase in the risk for gall bladder disease. There may be worsening of Migraine headaches with ERT, but this is not an absolute contraindication to ERT  







 You must not be on ERT for the following reasons:


1. Pregnancy


2. Unexplained vaginal bleeding.


3. Active or chronic liver disease.


4. History of breast cancer.


5. History of endometrial cancer except for very mild case (stage 1, grade 1).


5. Recent "blood clot formation" event  








 You should probably avoid ERT if you have any of the following:



1. High triglycerides level.


2. Past history of a "blood clot formation" event.


3. Family history of breast cancer.


4. Migraine headaches.


5. Seizure disorder.


6. Fibroid in the uterus.  



ERT should be prescribed by a physician knowledgeable in this field. Your physician should explain the benefits versus risks of ERT.


Your physician should carefully obtain your history to make sure that none of the absolute contraindications to ERT are present. Relative contraindications should be evaluated in individual patients.




Work-up Before starting ERT



A patient should have a normal breast examination, a normal mammogram, a normal pap smear, a normal blood test for liver function and a lipid panel before ERT is initiated and these tests should be repeated periodically during ERT.






If you still have your uterus, you need estrogen and progesterone.


Progesterone is used to counteract the increased risk for endometrial cancer which occurs when estrogen is used alone.


If you had a hysterectomy done in the past for reasons other than endometrial cancer, then you will need to be on estrogen alone.







Ovaries produce a small amount of testosterone. With menopause, testosterone production goes down and can cause decreased libido.


A consideration should be given to replace testosterone, especially if there is decreased libido.


The best way to achieve this goal is by taking DHEA 25 mg daily (available over the counter in the US). DHEA gets converted into testosterone inside the body. Oral methyltestosterone should be avoided as it can cause liver tumors.  




 Common estrogen preparations (used in the US):




Oral pills such as Premarin, Estrace or Ogen.


Skin patch such as Vivelle, Estraderm, Climara.


Skin spray such as Evamist




 Common progesterone preparation (used in the US)












 Combination pills




Prempro 2.5 and 5.0 contains 0.625 mg of Premarin and 2.5 or 5.0 mg of Provera.



Premphase contains 0.625 mg of Premarin daily for 28 days and 5 mg of Provera daily for 14 days only.



Combination skin patch: Combi-patch contains estradiol and norethindrone.




 Common side-effects of Estrogen






Breast tenderness.




Heavy menstrual bleeding.  




Common side-effects of Progesterone









Breast tenderness.  




How to minimize the side-effects:



Women differ greatly in their responses to different preparations of estrogen and progesterone.


Skin patches such as Vivelle cause less nausea and headaches than oral preparations such as Premarin, Ogen or Estrace.


Breast tenderness can be avoided by starting on a small dose of estrogen and then gradually increasing the dose.


Progesterone can be administered either on a daily basis with a smaller dose (continuous therapy) or for only 12-14 days of the month with a larger dose (cyclic therapy).


Switching from cyclic to continuous therapy may resolve some of the problems.


Vaginal bleeding occurs on a monthly basis if cyclic therapy is used.


Vaginal bleeding ceases to occur if continuous therapy is used, usually within 1 year.


If vaginal bleeding persists beyond one year, it should be investigated further by a gynecologist.    





This article was written by Sarfraz Zaidi, MD, FACE. Dr. Zaidi specializes in Diabetes, photoEndocrinology and Metabolism.


Dr. Zaidi is a former assistant Clinical Professor of Medicine at UCLA and Director of the Jamila Diabetes and Endocrine Medical Center in Thousand Oaks, California.





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